1. Field of the Invention (Technical Field)
The present invention relates generally to systems for providing meteorological information, particularly to apparatuses for supplying weather data to aircraft pilots, and specifically to a receiver and calculator apparatus for simultaneously receiving, processing, and displaying weather and other data to pilots of private aircraft.
2. Background Art
Historically, pilots of private aircraft have relied on a wind sock viewed from 1,000 to 1,500 feet while flying over a private airfield or heliport to determine wind speed and direction. More recently, in airports having tower operations or a fixed base operator, aircraft pilots have used radio voice communication with operators at the airport to obtain important weather information, including wind speed and direction. Within the last fifteen years at public airports in the United States, the federal government has installed automated weather observation systems (AWOS). AWOS measure airport weather conditions, and then broadcast periodically updated voice recordings to transmit the information to aircraft near the airport. This system was recently upgraded to a more sophisticated Automated Surface Observing System (ASOS) at the 1,000 largest public U.S. airports. The ASOS system provides a variety of weather information via voice radio communication to aircraft in the vicinity of the airport. Such automated systems can cost anywhere from $30,000 to $150,000 per airport. Both AWOS and ASOS require aircraft pilots to process audible (voice message) information from a radio receiver in the aircraft. There are about 5500 public airports in the United States that should 1 have automatic weather systems provided by the federal and local government to facilitate air safety for public air transportation. However, there are an additional 13,200 private airstrips, heliports, and seaplane bases that, due to cost constraints, will not be instrumented via these federal programs. There is a need, therefore, for a low cost, reliable, alternative system.
Meteorological information is important, of course, to pilots of small aircraft. Such weather factors as crosswind and headwind speed and direction, wind gust speed and direction, and dew point temperature inform the pilot's judgment, particularly during takeoff and landing. The pilot operating out of a small private airport may, at best, obtain some basic absolute wind speed and direction, barometric pressure, and temperature information from automated audio broadcasts from the facility, or from live audio radio communication from the fixed-base facility operator. At numerous remote airstrips, the pilot must still rely upon a wind sock, or upon regional weather reports. Still, even voice communications from a fixed base operator or automated broadcast leave the pilot with the task of referring to printed graphs, charts, and nomographs, and operating hand-held standard electronic calculators, or maybe even performing handwritten calculations, to determine from raw audio data such other vital information as cross wind and headwind speeds and directions, dew point temperature, and the like. Still further, the pilot should use the meteorological information thus determined to evaluate whether a takeoff or landing can be safely performed in his particular type of aircraft, under the given weather conditions, on a particular runway. Performing the task correctly is important, and desirably is not undertaken simultaneously with flying the aircraft and listening to the radio. Even when an assistant is available to perform the calculations, the opportunity for human error suggests the desirability of an apparatus which simplifies the task and minimizes error. A need remains, therefore, for a system and apparatus for receiving raw meteorological data and calculating therefrom additional derived meteorological and related information useable by a pilot, without the pilot having to be distracted while operating the aircraft itself. Against this background, the present invention was developed.